About 150 years ago, the three circuit elements, a resistor (R), a capacitor (C), and an inductor (L), were invented. An electric charge, a voltage, a current, and a magnetic flux vary in pairs to define a resistor (R), a capacitor (C), and an inductor (L). In these definitions, the electric charge, the voltage, the current, and the magnetic flux occur twice, except for the electric charge and the magnetic flux. In 1971, Leon O. Chua proposed a fourth circuit element by correlating the electric charge with the magnetic flux (Non-Patent Document 1). Since a change in the magnetic flux generates a voltage in the circuit elements of this type proposed so far, such an element has been considered as the fourth circuit element H that the generated voltage is correlated with the stored electric charge instead of directly correlating the magnetic flux with the amount of electric charge. The device with this correlation established is a pristine electrical device which cannot generate a magnetic flux. An example of such a device is a “memristor” (Patent Document 1 and Non-Patent Document 2), which raised an important point for discussion in the recent years. Such a so-called fourth circuit element exhibits a linear relationship between the stored electric charge and the resistance of the device. Eventually, the essential condition for the fourth circuit element is not met in the fourth circuit elements reported so far. Another major issue with this approach is that all of its properties could be generated by using combinations of L, C, and R (Non-Patent Document 1). Therefore, the circuit element H thus defined is not a fundamental element. In other words, the fourth circuit element has not been invented yet that demonstrates a linear relationship between the stored electric charge and the magnetic flux produced in the device. In this regard, Chua's paper in 1971 where he proposed the fourth circuit element for the first time is not correct, either. The reason is that therein, he could create any electronic properties of his proposed fourth element using a combination of L, C and R.
In recent years, it has become apparent that a so-called “memristor” is existing for nearly 40 years. A lot of papers published for almost half a century are now documented in Wikipedia (Non-Patent Document 3). At the same time, Chua has also admitted that his proposal in 1971 was not complete (Non-Patent Document 4). In order to generalize the proposal for the fourth circuit element, Chua has come up with two different devices, namely a mem-capacitor and a mem-inductor. Though Chua has mathematically formulated the mem-capacitor, no mathematical formulation has been proposed for the mem-inductor (Non-Patent Document 5). It should be noted that there cannot be three types of fourth circuit elements and instead of three it should be one. Chua has proposed that the practical realization of mem-capacitor and mem-inductor would be the next challenge. The present inventors have adopted here significantly distinct argument from that proposed by Chua to practically realize the fourth circuit element.
Invention of the fourth circuit element after 150 years of the invention of the first three circuit elements would open up a new world of electronics. Unlike the recently reported invention that claims memristor as the fourth circuit element, a true fourth circuit element H would directly correlate magnetic flux with the charge content in the device. In addition, electronic responses generated by the true fourth circuit element H (hereinafter referred also as device H) should be such that it would not be possible to regenerate those properties using a combination of L, C and R. The architecture of the new device H should be designed in such a way that it would generate a real magnetic flux not its electrical equivalence, which is the essential criterion for the fourth circuit element.
There have been attempts to fuse a capacitor and an inductor for generating new electronic properties (Patent Document 3). However, the concepts use conventional capacitors and the built up architecture is such that it in no way uses charge as a means to control the properties of the associated inductor. Therefore, there has been no attempt to build a hardware wherein fundamental properties of the capacitor that is charge tunes the fundamental properties of an inductor that is current flow. Internal charge storage of a capacitor can never tune the current flowing through the circuit unless it changes the resistance of the capacitor itself and the connecting path between two capacitors in the way simultaneously as a result of the charge storage. Therefore, an atomic scale control over the entire architecture is essential, which is not possible unless an integrated architecture is designed exemplifying the same principle with atomic scale design. Though there exists a device effectively exhibiting one to one correspondence between the stored charge and the electric flux, the above-explained device has not been realized, yet.